Carbon monoxide (CO) poisoning is one of the leading causes of boating fatalities in the US — and unlike fire or flooding, it gives no visible warning. A quality marine CO and propane alarm is one of the most important safety purchases you can make for your vessel. This guide walks you through what to look for and which units are worth your money.
Why You Need Both CO and Propane Detection
Many boaters assume a CO alarm covers everything. It doesn't. Propane and CO are two entirely different gases with different properties — propane sinks to the lowest point of the bilge, while CO disperses throughout the cabin. You need detection at different heights, or a combination alarm that handles both.
USCG Compliance: What's Required
The US Coast Guard recommends CO alarms on all vessels with enclosed sleeping spaces and fuel-burning systems. For propane-powered stoves or heating, propane detection is essential. Some state regulations and marina requirements go further — check your state's boating regulations for specifics.
What to Look For in a Marine Alarm
- Marine-rated housing — Standard household alarms cannot withstand marine humidity, vibration, and temperature swings. Look for units specifically rated for marine environments.
- Combination detection — A single unit covering both CO and propane/LPG reduces installation complexity and ensures no gaps in coverage.
- Audible + visual alert — In a loud marine environment or while sleeping, both audio and flashing LED alerts are important.
- Surface vs. flush mount — Surface mount installs quickly on any flat surface. Flush mount provides a cleaner look for finished cabin interiors.
- NMEA 2000 integration — Advanced units like the Digital Yacht CO Alert can send alarm notifications directly to your chartplotter display via the NMEA 2000 network.
Surface Mount vs. Flush Mount: Which Is Right for You?
Surface mount units are ideal for straightforward installations where aesthetics is secondary to function — utility areas, engine rooms, or galley overheads. The Safe-T-Alert 45 Series is a proven surface mount option with audible and visual alerts and a reputation for reliability across thousands of vessels.
Flush mount units sit recessed into the headliner or panel, creating a finished look consistent with premium interior builds. The Safe-T-Alert Combo Mini flush mount is a compact option that works well where space or panel depth is limited.
NMEA 2000 Integration: Worth It?
If your vessel has an NMEA 2000 backbone and a compatible MFD chartplotter, the Digital Yacht CO Alert adds a meaningful layer of safety by pushing CO alarm notifications to your helm display. This is particularly valuable for vessels where the helm and cabin are separated — you'll receive an alert while underway even if you can't hear the alarm below decks.
Browse the full selection of marine CO and propane alarms at Egret Marine and find the right configuration for your vessel.